Using Resources

• Ceramics are non-metal solids with high melting points that are not made from carbon-based compounds
• Clay and Glass are examples of ceramics
• Composites are made of one material embedded in another
• Fibres or fragments are surrounded by a matrix acting as a binder in a composite material
• Concrete and Fibreglass are examples of composites
• Polymers can have different properties depending on how it is made and what it is made from
• Low Density Poly(ethene) is made at moderate temperatures and high pressure and is used for bags and bottles
• High Density Poly(ethene) is made at lower temperatures and using a catalyst. It is more rigid and used for water tanks and drainpipes
• Thermosoftening polymers can be melted and remoulded
• Thermosetting polymers do not soften when heated
• Wood is a natural composite
• Ceramics are insulators of heat and electricity, brittle and stiff
• Polymers are insulators of heat and electricity, can be flexible and are easily moulded
• Composites depend on the matrix and reinforcement used to make them
• Metals are malleable, good conductors of electricity and heat, ductile, shiny and stiff
• Pure metals don't always have the properties needed
• Alloys are a combination of two metals to form a new metal with different properties.
• Bronze = Copper and Tin
• Brass = Copper and Zinc
• Gold Alloys are used to make jewellery
• Aluminium Alloys are used for aircraft
• Corrosion only happens on the surface of a material
• Iron and Steel corrode easily
• Both air and water are needed for iron to rust
• Painting a metal with plastic or electroplating prevents corrosion
• Using a sacrificial, more reactive metal means the iron will not be corroded
• An object that has been galvanised is sprayed with a zinc coating
• Copper-Rich ores are short in supply
• Bioleaching involves using bacteria on copper compounds to extract the copper into a soluble form
• Phytomining involves growing plants that contain copper and allow it to gradually build up in their leaves from which it can be harvested
• Life Cycle Assessments show the total cost involved in the production and life of a product, including the energy used in the production process.
• Life Cycle assessments can be biased
• Potable Water can be drunk
• Water is filtered to remove large sediment, first through a wire mesh then over gravel and sand beds
• After water is filtered, it is sterilised by bubbling chlorine gas or UV light
• Distillation can be used to desalinate water
• Water Waste can come from lots of different source including agriculture systems, sewage and Industrial processes
• Sewage treatment is the process of removing harmful substances from sewage.
• Sewage is first screened then undergoes sedimentation
• During sedimentation, sludge collects at the bottom whilst effluent floats to the top